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C-Pap vs Bi-Pap
#11
(10-29-2013, 04:50 PM)pdeli Wrote: Okay, it's too late to muddy the waters or make things more confusing.

So, I currently have a Remstar "Auto A-Flex" set at 7 cfm. My test of the Bi-Pap was set at 14 inhale and 7 exhale. I still think that I need a little more inhale and a little less exhale.

Am I correct that a C-Pap cannot do this?
Neither a plain CPAP nor an APAP can be set so that the inhale pressure (IPAP) is 14cm and the exhale pressure (EPAP) is at 7 cm. The Resmed S9's EPR system can allow up to a 3cm difference in pressure between inhalation and exhalation, but the proposed settings for your BiPAP have a PS = IPAP - EPAP = 7 cm, which is far greater than what the Resmed S9 CPAPs and APAPs can do with EPR set to 3. (Even at their max setting, the Flex systems on the PR machines provide even less pressure reduction than Resmed's EPR = 3 setting does.)

For what it's worth, the word "BiPAP" is PR's name for its bi-level PAP machine. The bi-level machine from Resmed is called a VPAP.

As PsychoMike points out, the PR BiPAPs and the Resmed VPAPs are at their heart, just fancier versions of a plain CPAP. But the BiPAP AutoSV Advanced and VPAP Adapt SV machines (along with the BiPAP ST and the VPAP ST machines) are a different animal altogether:

The CPAPs, APAPs, BiPAPs, and VPAPs do not have an algorithm that tries to trigger an inhalation from the patient. They treat OSA, but not CSA or CompSA because of this fact.

The BiPAP ST, BiPAP AutoSV Advanced, VPAP ST, and VPAP Adapt SV machines do have algorithms that trigger inhalations under certain specific conditions. That's why these machines are the ones that are needed to treat CSA and CompSA.
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#12
(10-29-2013, 05:18 PM)robysue Wrote: (Even at their max setting, the Flex systems on the PR machines provide even less pressure reduction than Resmed's EPR = 3 setting does.)

Pray, clarify? My understanding of a C-Flex, C-Flex+ and A-Flex setting of 3 means that the exhale pressure is reduced by 3 cmH2O, just like a ResMed EPR setting of 3. [ The timing of the pressure reduction cessation is different between the two, but the amount of pressure reduction is the same. ]
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#13
(10-29-2013, 04:50 PM)pdeli Wrote: Okay, it's too late to muddy the waters or make things more confusing.

So, I currently have a Remstar "Auto A-Flex" set at 7 cfm. My test of the Bi-Pap was set at 14 inhale and 7 exhale. I still think that I need a little more inhale and a little less exhale.

Am I correct that a C-Pap cannot do this?

Also, without knowing how my new Bi-Pap will be setup, if I feel that I want to change the settings, can I actually do that without going back to school?

Phil
Hi pdeli
If not mistaken, what they,re saying that you need 14 for optimum treatment and lesser exhale pressure at 7 which is the same as CPAP pressure shown in your profile. If you,re finding hard to exhale against the higher pressure (14) than breathing out at much lower pressure may helps.
APAP can be set the same way with minimum and maximum pressure but APAP does not gives you the same pressure support.
As APAP adjust pressure breath by breath through the night, might not have to go or stay at 14 all night





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#14
The short answer is yes you can learn to adjust your machine any way you want.
Careless random changes may cause ineffective treatment or be counter productive or even dangerous.

So as always no matter how expensive education seems, ignorance can be much worse.
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#15
From Phillips Respironcis: http://www.healthcare.philips.com/us_en/...orithm.wpd
Auto Algorithm
A smarter algorithm that maintains effective therapy at minimum pressures.

Proactive Performance
As the chart shows, the REMstar Auto algorithm can determine the optimal therapy level by proactively performing two types of tests (Pcrit and Popt). These tests not only help maintain pressure at a level in which obstruction is unlikely to occur, they also ensure that the pressure never becomes unnecessarily high.
[Image: advdet_proactive.jpg]
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#16
RonWessals Wrote:Pray, clarify? My understanding of a C-Flex, C-Flex+ and A-Flex setting of 3 means that the exhale pressure is reduced by 3 cmH2O, just like a ResMed EPR setting of 3. [ The timing of the pressure reduction cessation is different between the two, but the amount of pressure reduction is the same. ]

PR's description of the Flex systems can be found on the following PR webpages:

C-Flex: http://www.healthcare.philips.com/us_en/.../cflex.wpd
C-Flex+: http://www.healthcare.philips.com/us_en/...explus.wpd
A-Flex: http://www.healthcare.philips.com/us_en/.../aflex.wpd
Bi-Flex: http://www.healthcare.philips.com/us_en/...biflex.wpd

The critical thing in all the descriptions is that Flex is variable: The amount of pressure relief depends both on the Flex setting (1, 2, 3) AND on the user's individual exhalation effort for that particular breath. The following figure is the one for A-Flex:

[Image: a-flex_pressure_profile.gif]
The top curve represents the airflow into/out of the PAPer's lungs. The lower curve represents the pressure being delivered by the machine.

Notice that the pressure relief is NOT constant from breath to breath the way it is in the Resmed EPR system. The stronger the exhale, the more relief there is. In other words, the drop in pressure at the very beginning of the exhalation is proportional to the force of the exhale; it is NOT a reduction by a fixed amount of pressure.

The top humps on the pressure curve represent the current pressure setting. In A-Flex and C-Flex+ the pressure relief is done in two stages: There's the initial (more significant) drop at the start of the exhale and then the pressure is increased part way back to the current pressure setting for the rest of the exhale, with the pressure increasing all the way to the full (current) pressure setting at or near the beginning of the inhalation.

We can get a sense of the vertical scale on this graph when we note that the PR System One's Auto algorithm typically increases the pressure in increments of 0.5-1.0 cm units. Hence the vertical difference between top of the humps on the pressure curve are probably about 0.5-1.0 cm apart. Conveniently, the pair of dotted lines in the middle of that second graph are about the same distance apart as the top of the humps are. Hence that vertical distance most likely represents a difference of somewhere between 0.5-1.0 cm of pressure at most. And hence all settings of A-Flex (and C-Flex+) seem to deliver the same fixed amount of pressure relief during the second half of the exhale, and that amount of pressure relief is probably between 1 and 2 cm. For simplicity's sake, let's just assume that the pressure relief during the second half of the exhale is about 1.5 cm. The A-Flex (and C-Flex+) setting determines how much extra pressure relief is provided at the beginning of the exhale. On a very strong exhale, there may be as much as 3 cm of relief, but on a weak exhale, the relief will only be about 1.5 cm of relief, even with A-Flex (and C-Flex+) set to 2 or 3.

C-Flex provides significantly less pressure relief than either C-Flex+ or A-Flex does. The C-Flex pressure graph looks like this:
[Image: c-flex_pressure_profile.gif]
Notice that in C-Flex, the pressure returns to the full setting half way through the exhale. In other words, the only relief in C-Flex is the variable amount of relief provided at the beginning of the exhale. Since there is no scale on this graph, it is difficult to accurately judge the actual amount of pressure relief. But it is clear that the relief provided by C-Flex = 3 is NOT three times as great as that provided by C-Flex = 1. Hence, even on the most forceful exhalations, we can conclude that C-Flex = 3 is not likely reducing the the pressure by 3 cm
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#17
Zonk,

The chart you showed about the PR Auto algorithm also is applicable to the Auto algorithm used in the PR System One BiPAP Auto.

The main difference between the PR BiPAP Auto algorithm and the PR Auto algorithm is that on the PR BiPAP Auto, the (Pcrit and Popt) part of the algorithm is applied only to the IPAP pressure. EPAP stays the same until one of the following things happens:
  • Clusters of two or more OAs (or a cluster of Hs and OAs) occur within a minute or two. EPAP is raised to respond to clusters of OAs or clusters of Hs and OAs. But clusters consisting only of Hs will usually result raising the IPAP only.

  • Snoring is detected. (The PR BiPAP Auto is aggressive in increasing EPAP due to snoring, much to my tummy's displeasure.)

  • Max PS is reached and IPAP needs to be increased for some reason, including IPAP increases caused by the (Pcrit and Popt) part of the Auto algorithm.
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#18
(10-29-2013, 07:17 PM)robysue Wrote: The main difference between the PR BiPAP Auto algorithm and the PR Auto algorithm is that on the PR BiPAP Auto, the (Pcrit and Popt) part of the algorithm is applied only to the IPAP pressure. EPAP stays the same until one of the following things happens:
  • Clusters of two or more OAs (or a cluster of Hs and OAs) occur within a minute or two. EPAP is raised to respond to clusters of OAs or clusters of Hs and OAs. But clusters consisting only of Hs will usually result raising the IPAP only.

  • Snoring is detected. (The PR BiPAP Auto is aggressive in increasing EPAP due to snoring, much to my tummy's displeasure.)

  • Max PS is reached and IPAP needs to be increased for some reason, including IPAP increases caused by the (Pcrit and Popt) part of the Auto algorithm.

Hi robysue,

Thanks for a terrifically informative post.

The PR BiPAP Auto seems to be a more advanced machine than the ResMed S9 VPAP Auto.

Pressure Support is the pressure increase between EPAP and IPAP. The S9 VPAP Auto has only fixed, manually-adjustable Pressure Support. So, as the VPAP Auto automatically adjusts EPAP to avoid obstructive events (just like the AutoSet automatically adjusts its pressure), the IPAP remains a fixed pressure higher than EPAP.

The PR BiPAP Auto has settings for minimum Pressure Support and maximum Pressure Support, and it automatically adjusts PS within this range to optimize therapy. So, as the PR BiPAP Auto automatically adjusts EPAP to avoid obstructive events, the IPAP is a variable amount of pressure higher than EPAP, to further optimize therapy toward the goal (I suppose) of minimizing RERAs (Respiratory Effort Related Arousals) without raising the pressure unnecessarily high.

Take care,
--- Vaughn
Membership in the Advisory Member group should not be understood as in any way implying medical expertise or qualification for advising Sleep Apnea patients concerning their treatment. The Advisory Member group provides advice and suggestions to Apnea Board administrators and staff on matters concerning Apnea Board operation and administrative policies - not on matters concerning treatment for Sleep Apnea. I think it is now too late to change the name of the group but I think Voting Member group would perhaps have been a more descriptive name for the group.
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#19
Someday this may all make sense, but for now I'm waiting for my PR Bi-Pap.
At the risk of starting off in yet another direction, I don't understand why the IPAP and the EPAP aren't always different and if so, why the Bi-Pap is not the standard? (Or was that issue already explained in terms that flew ovwer my head?)

Phil

(11-03-2013, 05:37 AM)vsheline Wrote: [quote='robysue' pid='48185' dateline='1383092250']
The main difference between the PR BiPAP Auto algorithm and the PR Auto algorithm is ... (snip).....

..... Clusters of two or more OAs (or a cluster of Hs and OAs) occur within a minute or two. EPAP is raised to respond to clusters of OAs or clusters of Hs and OAs. But clusters consisting only of Hs will usually result raising the IPAP only.......(Snip)......

......IPAP increases caused by the (Pcrit and Popt) part of the Auto algorithm.[/list]

Hi robysue,

Thanks for a terrifically informative post.

The PR BiPAP Auto seems to be a more advanced machine than the ResMed S9 VPAP Auto. .....(snip).....

......The PR BiPAP Auto has settings for minimum Pressure Support and maximum Pressure Support, and it automatically adjusts PS within this range to optimize therapy. So, as the PR BiPAP Auto automatically adjusts EPAP to avoid obstructive events, the IPAP is a variable amount of pressure higher than EPAP, ...(snip)....

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#20
I'm not a guy with all the answers - the *reason* for going to a bilevel (bipap/vpap/etc) machine is so you *can* have the EPAP and IPAP at different rates.

Pressure Support = the difference between EPAP and IPAP. Most machines want you to set EPAP (everything but inhale pressure), then add PS, to get IPAP (inhale pressure).

Example: Before I had my nose and throat surgery, I was on a CPAP with a pressure of 19. It was very hard for me to exhale, it kept waking me, and blowing air out my lips - so my sleep doc switched me to a VPAP (a Resmed bilevel machine). My manual numbers were EPAP 10, IPAP 19. After the surgeries, the manual numbers were changed to EPAP 7, IPAP 13. Switching to 'autoset' mode, you do not set the IPAP, but rather the EPAP and PS - the machine will raise the EPAP as needed, and keep the PS the same (thereby changing the IPAP as needed) - other machines can change both EPAP and PS - with ranges set for both.

Personally, I do not know anyone with their EPAP and IPAP at the same setting, and, if so, why they would do so?

Many people have a hard time adjusting to a bilevel machine, so DRs tend to hesitate to put people on them. I personally love using one. (compared to a CPAP)

Does that answer your question?
*I* am not a DOCTOR or any type of Health Care Professional.  My thoughts/suggestions/ideas are strictly only my opinions.

"Only two defining forces have ever offered to die for you. Jesus Christ and the American Soldier. One died for your Soul, the other for your Freedom."
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